copy_process() handles CLONE_NEWUSER before the rest of thenamespaces. So in the case of clone(CLONE_NEWUSER|CLONE_NEWUTS)the new uts namespace will have the new user namespace as itsowner. That is what we want, since we want root in that newuserns to be able to have privilege over it.

Changelog: Feb 15: don't set uts_ns->user_ns if we didn't create a new uts_ns. Feb 23: Move extern init_user_ns declaration from init/version.c to utsname.h.